With the rapid development of mobile communication technology and the coming of the third generation (3G) digital communication era, the mobile terminal has become a necessary for the daily life of people. But with the development, the use of the mobile terminal also brings people a lot of harassments which mainly lie in: the harassing call, which is called generally from an unknown number and is hung up immediately after the ringing lasts less than three seconds, wherein if the user calls back, the call may be an audio message lottery fraud trap or the user has been charged with high information fees, therefore the people who can not power off the mobile terminal at night are often woke up by the harassing call or the junk message which has seriously affected the sleep. Consequently, the user has paid more and more attention to the mobile terminal with the function of filtering the harassing call, and the “call firewall” function emerges because of the demand.
At present, most terminal manufacturers provide the call firewall function to adapt the demand of the user. The implement method thereof is mainly as follows: firstly presetting a blacklist in the terminal; and matching the call number with the numbers in the blacklist one by one when the terminal is called, wherein it does not indicate the user of the call but hangs up the phone automatically if the call number matches with the number in the blacklist; and indicates the user of the call normally if the call number does not match with the number in the blacklist. Some existing terminal call firewalls achieve the filtration purpose by mainly using the method of adding blacklist and friends list, and selecting the options such as “forbidding blacklist”, “allowing friends”, “forbidding all”, “cancelling all restrictions” and so on. Currently there are some other call firewalls which realize the method of matching number wildcard, e.g. the blacklist can be set with “159*”, “*1362222222”, “15033333??” and so on, making the function more flexible.
However, all existing solutions have some defects. Firstly, there is not any method to identify the harassing call automatically, and the blacklist has to been added manually. For the great deal of random harassing numbers, it is extraordinary inconvenient to use this kind of firewall, which has rather bad actual effect. Secondly, the solution does not consider the situation that the harassing number is recovered by the operator. Generally speaking, one harassing number will be ceased after emerging for 1-3 months because of owing the fees or being reported, and then will be recovered by the operator after another 3-6 months, and will be sold out eventually. At this time, the user of this number is not the original user of the number in the backlist any more. The existing implement method of firewall blacklist does not consider this issue, with the result that the user can not learn which number has been recovered already when facing the increasingly enormous blacklist. These blacklists occupy a great deal of resource space. New harassing number emerges continually but can not be filtered effectively, which seriously affects the efficiency of using the mobile terminal and eventually results in that the user gives up using the call firewall function.